Google is winning the smartphone war globally, helped in large part by low-end devices selling in huge volumes throughout emerging economies. But the battle between Android and the iPhone is much closer than you might expect in the largest mobile markets, especially in developed countries.

Mobile researcher Flurry presented data this week at the Game Developers Conference in San Francisco showing how smartphone and tablet gamers spend their time. The chart above illustrates the split between Android and iOS device users actively downloading and playing games in the top five markets.

The playing field looks pretty evenly divided — except in South Korea. The country, which Flurry describes as the world's first saturated smartphone market, has mostly shunned the iPad and iPhone. Koreans favor the home team, Samsung Electronics, and its Android-based phone-tablet hybrids.

"South Koreans love their phablets," Torrey Lincoln, Flurry's senior director of games business development, said during his GDC presentation.

Apple is the winner in Japan, but that's not the same as a victory in China. There are 251 million iOS and Android devices used for playing games in China, according to Flurry. In Japan, there are 33 million. The U.S. is closer, at 238 million, but it's not growing as fast as China.

"It's pretty clear that the age of Android global dominance is here," Lincoln said. "Worldwide, the future for Android looks bright."

More volume doesn't always mean more profits, and that extends to game developers. The average price of an Android app is 6 cents, Flurry said. For Apple products, it's 19 cents on the iPhone and 50 cents on the iPad.

Game makers can tap other business models beyond requiring payment upfront. For example, "Candy Crush Saga" makes a fortune off of selling extras within the app. "Flappy Bird" was mining millions of eyeballs looking at ads before the game's Vietnam-based creator Dong Nguyen pulled the app down. He's also at GDC this week, by the way, and he said "Flappy Bird" is coming back.